cp's OEIS Frontend

A265751 Square array A(row,col): A(row,0) = row and for col >= 1, if A082284(row) is 0, then A(row,col) = 0, otherwise A(row,col) = A(A082284(row),col-1).

%I A265751 #14 Dec 23 2015 14:08:06
%S A265751 0,1,1,3,3,2,5,5,6,3,7,7,9,5,4,0,0,11,7,8,5,0,0,13,0,0,7,6,0,0,0,0,0,
%T A265751 0,9,7,0,0,0,0,0,0,11,0,8,0,0,0,0,0,0,13,0,0,9,0,0,0,0,0,0,0,0,0,11,
%U A265751 10,0,0,0,0,0,0,0,0,0,13,14,11,0,0,0,0,0,0,0,0,0,0,20,13,12,0,0,0,0,0,0,0,0,0,0,0,0,18,13,0,0,0,0,0,0,0,0,0,0,0,0,22,0,14
%N A265751 Square array A(row,col): A(row,0) = row and for col >= 1, if A082284(row) is 0, then A(row,col) = 0, otherwise A(row,col) = A(A082284(row),col-1).
%C A265751 The square array A(row>=0, col>=0) is read by downwards antidiagonals as: A(0,0), A(0,1), A(1,0), A(0,2), A(1,1), A(2,0), A(0,3), A(1,2), A(2,1), A(3,0), ...
%C A265751 Each row n lists all the nodes in A263267-tree that one encounters when one starts from node with number n and always chooses the smallest possible child of it [given by A082284(n)], and then the smallest possible child of that child, etc, until a leaf-child (one of the terms of A045765) is encountered, after which the rest of the row contains only zeros.
%F A265751 A(row,0) = row and for col >= 1, if A082284(row) is 0, then A(row,col) = 0, otherwise A(row,col) = A(A082284(row),col-1).
%F A265751 A(0,0) = 0, A(0,1) = 1; if col = 0, A(row,0) = row; and for col > 0, if A(row,col-1) = 0, then A(row,col) = 0, otherwise A(row,col) = A082284(A(row,col-1)).
%e A265751 The top left corner of the array:
%e A265751    0,  1,  3,  5,  7,  0,  0,  0,  0
%e A265751    1,  3,  5,  7,  0,  0,  0,  0,  0
%e A265751    2,  6,  9, 11, 13,  0,  0,  0,  0
%e A265751    3,  5,  7,  0,  0,  0,  0,  0,  0
%e A265751    4,  8,  0,  0,  0,  0,  0,  0,  0
%e A265751    5,  7,  0,  0,  0,  0,  0,  0,  0
%e A265751    6,  9, 11, 13,  0,  0,  0,  0,  0
%e A265751    7,  0,  0,  0,  0,  0,  0,  0,  0
%e A265751    8,  0,  0,  0,  0,  0,  0,  0,  0
%e A265751    9, 11, 13,  0,  0,  0,  0,  0,  0
%e A265751   10, 14, 20,  0,  0,  0,  0,  0,  0
%e A265751   11, 13,  0,  0,  0,  0,  0,  0,  0
%e A265751   12, 18, 22, 25,  0,  0,  0,  0,  0
%e A265751   13,  0,  0,  0,  0,  0,  0,  0,  0
%e A265751   14, 20,  0,  0,  0,  0,  0,  0,  0
%e A265751   15, 17, 19,  0,  0,  0,  0,  0,  0
%e A265751   16, 24,  0,  0,  0,  0,  0,  0,  0
%e A265751   17, 19,  0,  0,  0,  0,  0,  0,  0
%e A265751   18, 22, 25,  0,  0,  0,  0,  0,  0
%e A265751   19,  0,  0,  0,  0,  0,  0,  0,  0
%e A265751   20,  0,  0,  0,  0,  0,  0,  0,  0
%e A265751   21, 23, 27, 29, 31, 35, 37,  0,  0
%e A265751   22, 25,  0,  0,  0,  0,  0,  0,  0
%e A265751   23, 27, 29, 31, 35, 37,  0,  0,  0
%e A265751   ...
%e A265751 Starting from n = 21, we get the following chain: 21 -> 23 -> 27 -> 29 -> 31 -> 35 -> 37, with A082284 iterated 6 times before the final nonzero term 37 (for which A060990(37) = A082284(37) = 0) is encountered. Thus the row 21 of array contains terms 21, 23, 27, 29, 31, 35, 37, followed by an infinite number of zeros.
%o A265751 (Scheme)
%o A265751 (define (A265751 n) (A265751bi (A002262 n) (A025581 n)))
%o A265751 (define (A265751bi row col) (cond ((zero? col) row) ((A082284 row) => (lambda (lad) (if (zero? lad) lad (A265751bi lad (- col 1)))))))
%o A265751 ;; Alternatively:
%o A265751 (define (A265751bi row col) (cond ((zero? col) row) ((and (zero? row) (= 1 col)) 1) ((zero? (A265751bi row (- col 1))) 0) (else (A082284 (A265751bi row (- col 1))))))
%Y A265751 Cf. also A000005, A045765, A060990.
%Y A265751 Column 0: A001477, Column 1: A082284.
%Y A265751 Cf. A266111 (number of significant terms on each row, without the trailing zeros).
%Y A265751 Cf. A266116 (the rightmost term before trailing zeros).
%Y A265751 See also array A263271 constructed in the same way, but obtained by following always the largest child A262686, instead of the smallest child A082284.
%Y A265751 Cf. also tree A263267 (and its illustration).
%K A265751 nonn,tabl
%O A265751 0,4
%A A265751 _Antti Karttunen_, Dec 21 2015